1. Field of the Invention
This invention relates to musical instruments and in particular to switching mechanism for use in controlling electrical switches utilized in such musical instruments.
2. Description of the Prior Art
It is conventional in musical instruments, such as electronic organs, to utilize a plurality of stop tablets for controlling tone characteristics produced by the organ. Illustratively, such stop tablets are provided for introducing clarinet effects, trumpet effects, etc.
At times, it is desirable to utilize two such effects, or characteristics, concurrently. Thus, it is desirable to provide means for maintaining one or more of the tablets depressed as desired by the player of the instrument.
It is further desirable in such material instruments to cause the release of a previously selected tablet when a newly selected tablet is depressed. It is desirable that such release be effected without the need for manipulation of the previously selected tablets.
One organ structure providing stop tablet control of the tone selection is illustrated in U.S. Pat. No. 3,136,869 of Lyman J. Haviland. As shown therein, operation of any tablets causes a pivoting of a rocker arm to engage any one of a plurality of plungers which may have been previously placed in an operated position. The engagement effects a return of the plungers to a normal position under the pressure of a number of arms provided in the apparatus. The plungers, on returning to their normal position, align with detent portions on spring blades of the apparatus to permit the blades to disengage and interrupt any circuit previously completed thereby.
In U.S. Pat. No. 3,084,584 of Amedeo Iorio, an electrical musical instrument comprising an accordian-organ combination is shown having a plurality of organ stop flaps provided with switch means. Each flap is pivoted on a suitable pivot pin and mechanically linked to the vent shutters of the keyboard. A leaf spring is provided for restoring a bar flap whenever another key is depressed. The flap actuates three-pole switches. The flap is retained in a depressed position by a leaf spring engaging a recess to hold the flap in the depressed position until a counter-vailing force is brought to bear thereagainst as by depression of another flip.
Howard M. Thomas et al, in U.S. Pat. No. 3,420,131, disclose a stop tablet assembly having a rock shaft on which the stop tablets are mounted for selective movement between first and second positions. A plurality of cams are mounted on a cam shaft to be engaged with projections extending from the stop tablets. Upon movement of the cam shaft, the cams are moved against all of the stop tablets in the second position which are thereby returned to the first position. Operation of the rock shaft causes the operators aligned with a respective stop tablet setting means to move the tablet from the first to the second position.
In U.S. Pat. No. 3,306,995, Donald J. Campbell shows a switch control having release means mounted on a frame and normally positioned to be contacted by any one of a plurality of actuators when any one of the actuators is in a second position. Resultingly, movement of any one actuator into an override position enables biasing means of the mechanism to move all other actuators to the first position. The device is directed to the control of double touch actuation and more specifically utilizes felt pads which may move upwardly through an aperture in a base plate to permit an upward movement of a bar member for raising detent springs away from a plurality of tab pins to release the detent action whereby all tabs except the tab being actuated are released from the "on" position.
Swedish Pat. No. 1,761 shows a tab control wherein a manually operable pushbutton G is arranged to release an arm E thereby to release the tabs.